UNION — Sara Williams spent her 90th birthday exactly where she wanted to be — at her job in the registrar’s office at Kean University.

What began as a two-week temp job for the school in the ‘70s has lasted 38 years, and Williams has no interest in slowing down. She still drives to work each morning from her home in Hillside, and is responsible for processing all the school’s transcripts.

“I have to do something, I don’t want to sit home and twiddle my thumbs,” Williams said at her office birthday party Tuesday, where she was surrounded by dozens of friends, all of them eager to tell stories about the French-born World War II survivor.

“She’s phenomenal, there’s no one else like her,” said Ken Wolpin, who runs the office. “She’s been through software upgrades, platform upgrades. She’s amazing, she could run circles around everyone here.”

In her spare time Williams has a passion for sewing, and co-workers said she hems clothes for everyone in the office. She works four days a week now, but insists she would be at the office every day, if allowed.

Williams' son said that when a snowstorm and a holiday expanded a recent weekend to five days, his mother almost lost her mind, cooped up in the house.

“Oh, what a bear. I said, ‘Ma, you got five days off!’ She said, ‘Oh my God, what am I gonna do?’ ” Elliot Williams said. “She needs to come here, or life isn't right.“

Robin Rajs was a student worker in the Kean registrar’s office when she asked Williams, a friend of her mother, if she wanted to come in for a few weeks to stuff envelopes. Rajs later moved around departments at the university, from the registrar to admissions to counseling, and retired in 2011.

“And Sara’s still here,” she said with a laugh.

But there's much more to Williams' story.

Williams grew up in Paris and was a teenager when the Germans invaded and occupied the city in 1940. As Jews, her family was forced into hiding from the Nazis, who were rounding up citizens and sending them to concentration camps.

In this photo snapped minutes before they met, Abe Williams poses at left, while his future wife climbs a statue on the right.

“If you were able to hide, you survived. So when everybody tells me I survived, I don’t think of myself as a survivor, because I never went to the camps,” she said.

A woman in the city agreed to hide Williams, her brother and her parents, but because she lived alone, the family had to remain silent every day until she came home from work, Williams said.

After a year of hiding, Williams' parents found a family willing to shelter her and her brother near Marseilles in the south of France, where the Nazis were not in control. The two of them lived there until Allied forces liberated Paris in 1944.

When World War II ended, Williams brought a friend from Marseilles to see the Eiffel Tower in Paris, but the structure was closed to everyone except soldiers. So she grabbed the first GI she could find, an American named Abe Williams, and decided to ask a favor.

“I don’t know why I opened my mouth, but I asked him, ‘Could you take us up to the tower?’ He said, ‘Sure, why not,’ and that was it,” she said.

She chatted with the young soldier and gave him her address, expecting him to throw it in the trash, she said. But a week later he was at her door, asking to come in for dinner.

By 1947 the two were married, and they stayed together for the next 55 years, until his death in 2002.

At 90, Williams is spry and sardonic, deflecting compliments and insisting that her boundless work ethic is nothing special.

“The thing about Sara is, everyone loves her so much and she’s touched so many people, and she doesn’t have a clue,” Rajs said.

“Not really,” Williams responded, when a co-worker leaned in to tell her she was amazing. “I don’t understand why.”

At the party, Williams’ boss handed her an oversized birthday card covered in signatures and messages. She shook her head in disbelief as she read over the notes written by some of the people she’s meant something to during the past four decades.

“Are you kidding me,” she said quietly, her eyes welling with tears.

“She’s so humble,” Rajs said, “she doesn’t realize the impact she’s had on so many people.”